SAFO can be setup to run on more than one computer that can communicate with each other in order to share responsibilities to run smooth operations even if for some reason one computer fails. For this all computers involved need to have access to a database on the internet, where the information are exchanged.
Each SAFO installation can be configured as a user of such a database. A unique ID is assigned to identify each user. Every time a user accesses the database, a timestamp is placed there to keep track who had the last access. The database access logic uses this to determine which user has currently control over the system while the others are on standby. If for some reason the controlling user is failing to update his timestamp, the database will give the control to another user, after putting the original user on standby. This makes sure that the equipment is under continued control – after a short interruption when the transition is happening.
There is no limit on how many users can share the responsibilities. The equipment to be controlled by the users does not have to be the same for all users – it is up to the administrative setup to make sure the equipment coverage is complete and sufficient.
In the current implementation, SAFOs can share the responsibilities to run the schedules for one or more Air Conditioning Units. If those schedules are modified via the simplified user interface for AC scheduling, the changes will be communicated to the other SAFO installations sharing the database – it does not matter whether the changes are entered on the active or a standby SAFO. In fact, a tenant version of SAFO allows changes to be made the same way, however the tenant version allows only access to the scheduling for ACs the tenant is authorized for – it is not involved in the actual running of the schedules.